The present invention relates to systems an articles for assembling structural framing components. More particularly, the invention pertains to methods and apparatus for erecting habitable structures.
Western construction methods are not particularly tolerant of seismic vibration. These methods are characterized by assemblies of rigid but friable materials such as brick, stone and mortar. Although modern commercial construction usually relies upon a steel superstructure that is paneled with masonry and plaster, the steel load bearers are heavily stressed and joined by welded or riveted shear joints. When whipped by the high amplitude, low frequency ground movement of a seismic disruption, welds are broken and rivets are sheared and the steel superstructure collapses.
Others have observed that construction methods and materials used by native cultures of the Pacific Rim are very earthquake tolerant. Significant characteristics of this technology include the use of wood and bamboo assembled by leather thongs, grass and leaves. Timbers are joined without nails or pegs. Rather than rupture, such joints merely slip in their lashings or sockets.
Although primitive construction methods and materials may be earthquake survivable, they also are not particularly fire or rot resistant. Neither are such construction methods particularly weathertight, draft resistant or suitable for multistory structures.
However, the central essence of these earthquake resistant construction methods is not so much in the indigenous materials used but in the absence of rigidly joined points of high load and stress concentration. It is in the capacity of the structural joints to yield, slip and twist without stressing the fasteners or load bearers beyond the point of failure that distinguishes the primitive Pacific construction methods for being earthquake proof.
It is, therefore, an object of the present invention to provide some construction assembly techniques that adapt the primitive low stress joint technology to modern, high strength materials.
Another object of the present invention is to provide methods and apparatus for erecting habitable structures with ferrous, non-ferrous metallic or plastic tube but without welding or threaded fasteners.